JPH1185110A - Display device and display method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease color breakups and white braekups and to eliminate pseudo contours by making display action with the octuple speed field sequential signals formed to output red(R), green(G), blue(B) and white(W) signals twice each in a period of one frame and the white signal so as to continue for two field periods. SOLUTION: The output of the octuple speed field sequential signals formed to output the R, G, B and W signals formed by a display control signal forming means respectively twice each in one frame period and to output at least the W signals so as to continue in the two field periods is executed and the display action is executed by these octuple speed field sequential signals. In such a case, an octuple speed field sequential control section executes the control to change over the selectors by each of 1/8 frame (=1 field) within the one frame period. For example, the R signals, G signals and B signals as, for example, the frame F are stored into the frame memories and are thereafter read out of the frame memories repetitively 8 times at the octuple speeds in the period when the frame F2 is inputted and are processed in a white signal forming section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a display device and a display method, and more particularly to a technique for performing color display by a frame sequential signal.

[0002]

2. Description of the Related Art Various types of display devices have been developed, such as a so-called housing-type monitor device and a head-mounted display in which a small liquid crystal display panel or the like is arranged in a substantially eyeglass-type housing. These display devices are required to have higher resolution.

[0003] One technique for increasing the resolution is a time-division screen sequential display method. For example, 3 using an RGB signal
In the double-speed time-division screen sequential display method, one frame period is set to three.
The signal is divided (time-divided into three fields) to output a triple speed R signal in the first field, a triple speed G signal in the next field, and a triple speed B signal in the last field. In such a display unit to which the triple-speed time-division plane sequential signal is supplied, display by an R signal in the first field period of one frame, display by a G signal in the next field period, and display by a B signal in the last field period. , Thereby realizing a one-frame color image display.

In order to further increase the resolution,
A quadruple-speed time-division plane sequential method has also been considered. For example, FIG.
0, the minimum value detection unit 61 and the subtractors 62, 6
At steps 3 and 64, a red signal R ', a green signal G', a blue signal B ', and a white signal W are input from the input RGB color signals (red signal R, green signal G, blue signal B) for display control. Generate That is, the minimum value detection unit 61 detects the minimum value of each of the signal R, the signal G, and the signal B and sets it as a white signal W, and the subtractors 62, 63, and 64 detect the signal R, the signal G, and the signal. A red signal R ′ (= R−W), a green signal G ′ (= GW), and a blue signal B ′ (= B−W) are generated by subtracting the white signal W from each of B.

[0005] Each of the red signal R ', green signal G', blue signal B 'and white signal W generated in this manner is a quadruple speed signal. Then, the period of one frame is divided into four (time division into four fields). For example, a quadruple speed signal R 'in the first field, a quadruple speed signal G' in the next field, and a quadruple speed signal B 'in the next field. , A quadruple speed signal W is output in the last field. Such 4
In a display unit to which a double-speed time-division plane sequential signal is supplied, a display by a signal R 'in the first field period of one frame, a display by a signal G' in the next field period, a display by a signal B 'in the next field period, The display by the signal W is performed in the last field period, thereby realizing a one-frame color image display.

[0006]

By the way, the above 3)
The double-speed plane sequential method and the quadruple-speed plane sequential method have the following problems, respectively.

FIG. 11A shows a state on a screen when a certain display is performed in the triple speed plane sequential system.
(B) shows the state on the retina of the person watching the image at that time. In the vertical direction of FIG. 11A, 1V (one frame) is arranged on the time axis to show two frames, and the horizontal axis shows the moving direction of the image. That is, by displaying the image of the lower frame following the image of the upper frame, the edge of the displayed image moves rightward in the drawing. The numbers in the figure correspond to the luminance levels.
The points MA and MB as arrows pointing to the lower right in the figure are as follows:
Indicates a point on the viewer's retina. When considering the movement of the display image as shown in these two frames, the eyeball of the viewer follows the movement of the display image, whereby the MA point and the MB point on the retina relatively move with respect to the image. It will move like an arrow.

FIG. 11B shows the state of an image for two frames with the MA point and MB point on the retina as reference (fixed) when the eyeball follows. The lower part of (b) shows an image (color) recognized on the retina (the horizontal axis is a position on the retina). This FIG.
(B) As can be seen from the lower part, the edges of B, G, and R are shifted on the retina, and the viewer recognizes a bluish hue as a whole at the edge portion of the image. That is, color breakage of the edge occurs.

On the other hand, FIG. 12 shows a case of the quadruple speed sequential method. The notation format of the figure is the same as that of FIG.
FIG. 12A shows the relative movement between the MA point and the MC point on the retina due to the movement of the eyeball to the movement of the image of two frames, and FIG. 12B shows the fixation of the MA point and the MC point on the retina. 5 shows a state of an image to be recognized in the case of performing. This FIG.
As apparent from (b), 4 including the white signal W
By adopting the double speed plane sequential method, it is possible to eliminate the color breakage of the moving edge between the achromatic colors, which has occurred in the case of the triple speed plane sequential processing.

However, in this quadruple-speed plane sequential system, a white signal W is generated to reduce color breakup at a moving edge portion between achromatic colors, and an image is represented by a signal W component as much as possible. For this reason, when the eyeball follows a moving edge portion of a single color change in which a change in the white signal W is large, there is a problem that a white crack which is not seen in the triple speed plane sequential method occurs.

FIGS. 13 and 14 show the white signal W, respectively.
The state when the eyeball follows the moving edge portion of a single color change having a large change in the case of the triple speed plane sequential method and the quadruple speed plane sequential method is shown. In the case of the triple speed plane sequential method, as shown in FIG. 13A, even if there is a relative movement between the MA point and the MD point on the retina due to the movement of the eyeball to the movement of the image of two frames, As shown in FIG. 13B, no color break occurs at the image edge recognized between the MA point and the MD point on the retina. However, in the quadruple speed sequential method, as shown in FIG. 14A, when there is a relative movement between the MA point and the MB point on the retina due to the movement of the eyeball with respect to the movement of the image of two frames, FIG. M on the retina as
A whitish hue is recognized as an image edge recognized between the point A and the MB point. This is a so-called white crack.

As a countermeasure against such white cracks in the quadruple speed sequential method, an eightfold speed sequential method can be considered.
That is, one frame is divided into eight fields, and a signal R ′, a signal G ′, a signal B ′, a signal W, a signal R ′, a signal G ′, a signal B ′, and a signal W are sequentially output in the order of: The display is performed. FIG. 15 shows this 8 × speed plane sequential method. As shown in FIG. 15A, the relative movement of the MA point and the MB point on the retina due to the movement of the eyeball with respect to the movement of the image of two frames is shown. If there is, the state of the image edge recognized between the MA point and the MB point on the retina is as shown in FIG. That is, as can be understood from comparison with FIG. 14, the level of the white crack can be reduced as a moving edge portion of a single color change in which the component of the white signal W is large. However, even if such a level of white cracks can be reduced, if the moving speed of the edge increases, two white cracks occur as shown in the figure, and the moving edge portion between the achromatic colors has a thin line (pseudo contour) next to the edge. ) Occurs.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a display device and a display method with a higher resolution which can reduce color breaks and white breaks and eliminate false contours. And

For this purpose, the input R
Display control signal generating means for generating a red signal, a green signal, a blue signal, and a white signal, which are signals of a field period obtained by dividing one frame period into eight, as display control signals from the GB color image signal; In the frame period, each of the red signal, the green signal, the blue signal, and the white signal generated by the display control signal generating means is twice, and at least the white signal is continuous for two field periods. And a display means for performing a display operation in response to an 8 × speed sequential signal output from the plane sequential output means. In other words, an 8 × speed time-division plane sequential signal in which the field by the white signal is continuous twice is generated, and the display means is driven to perform color display. Reduces the phenomenon of white cracks.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a display device according to an embodiment of the present invention will be described. FIG. 1 is a block diagram of the display device according to the embodiment. This display device is supplied with RGB primary color signals (R signal, G signal, and B signal) as color video signals, and the R signal, G signal, and B signal are each converted into digital data by the A / D converter 1. Is converted to R signal and G signal output from the A / D converter 1 as 8-bit data, for example.
The signal and the B signal are written into the frame memory 3 respectively.

In this embodiment, the display is performed in the 8 × -speed sequential mode, and an 8 × -speed sequential control unit 2 is provided for this purpose. The 8 × speed plane sequential control unit 2 performs various timings for performing the 8 × speed plane sequential processing using the horizontal synchronization signal HD and the vertical synchronization signal VD supplied along with the input R signal, G signal, and B signal. A signal is generated to control the read / write operation of the frame memory 2, the switching operation of the selector 8, the control of the liquid crystal panel drive control unit 11, and the control of the backlight surface sequential drive control unit 15. The 8 × speed plane sequential control unit 2 sends the R signal, G signal, B signal
A write clock synchronized with the dot clock of the signal is supplied, and writing of the R, G, and B signals from the A / D converter 1 is executed.

At the same time, the 8 × speed plane sequential control unit 2 supplies a read clock eight times the dot clock to the frame memory 3, and the R clock stored in the frame memory 3.
The signal, the G signal, and the B signal are read. That is, an R signal, a G signal, and a B signal are read out as data at 8 × speed. It is needless to say that the writing / reading area and timing are set so that the overwriting on the memory such that the unread data portion is overwritten by the writing operation to the frame memory 3 does not occur. Absent.

The R, G, and B signals read from the frame memory 3 are applied to the inverse gamma correction units 4, 5, 6, respectively.
To return to a state in which the inverse γ correction, that is, the γ correction is not applied. Then, it is supplied from the inverse γ correction units 4, 5 and 6 to the white signal generation unit 7. White signal generator 7
Has a minimum value detection unit 7d and subtracters 7a, 7b, 7c. Then, R input from the inverse γ correction units 4, 5, and 6
The signal, G signal, and B signal are subtracted by subtracters 7a, 7b,
7c and to the minimum value detection unit 7d. The minimum value detector 7d detects the minimum value of each of the R signal, the G signal, and the B signal, and supplies the detected minimum value as a white signal W to the TW terminal of the selector 8. The subtractor 7a
Subtracts the white signal W from the R signal to obtain a signal R ′ (=
RW) is generated and supplied to the TR terminal of the selector 8.
The subtractor 7 b generates a signal G ′ (= GW) by subtracting the white signal W from the G signal, and supplies the signal G ′ (= GW) to the TG terminal of the selector 8. The subtractor 7 c subtracts the white signal W from the B signal to generate a signal B ′ (= B−W) and supplies the signal B ′ (= B−W) to the TB terminal of the selector 8.

The R signal, the G signal, and the B signal read from the frame memory 3 are eight times speed signals, and are read eight times (8 fields) repeatedly in one frame period. Accordingly, the signal R 'of one field, eight times faster, is supplied to the TR terminal of the selector 8 every ８ frame period during one frame period. The same applies to the terminals TG, TB, and TW.
The double-speed signal G ′, the signal B ′, and the signal W are supplied.

The 8 × speed plane sequential control unit 2 includes a selector 8
Is controlled every ８ frame (= 1 field) within one frame period. In this example, the order of the eight switching operations in one frame period is determined by the terminal TR → the terminal TG.
→ Terminal TB → Terminal TW → Terminal TW → Terminal TB → Terminal TG
→ The 8 × speed plane sequential control unit 2 performs the switching control so as to be the terminal TR. Therefore, the selector 8 outputs the signal R ′ → signal G ′ → signal B ′ → signal W → signal W → signal B ′ → signal G ′ → signal R ′ as an 8 × speed sequential signal during one frame period.
Are output in this order.

FIG. 2 shows an image of an 8 × speed plane sequential signal. 2A, 2B, and 2C show two frames (F1, F2) of the input R signal, G signal, and B signal. For example, the R signal, the G signal, and the B signal as the frame F1 are shown. After the signal is stored in the frame memory 3, the frame F2
Are repeatedly read eight times at 8 × speed from the frame memory 3 during the input period, and processed by the white signal generator 7 as described above. The output is selected and output by the selector 8 for each ８ frame period in the above order, so that the 8 × -speed plane sequential signal output from the selector 8 is as shown in FIG.

A signal output from the selector 8 as an 8 × speed plane sequential signal is supplied to the γ correction circuit 9 by the liquid crystal panel 1.
4 is subjected to γ correction processing according to the VT characteristic. Then, the γ-corrected 8 × -speed plane sequential signal is returned to an analog signal by the D / A converter 10. The 8 × speed plane sequential signal output from the D / A converter 10 is subjected to polarity inversion and line inversion every １ ／ frame period in the field inversion circuit 12. The timing and line timing for each ８ frame are provided from the liquid crystal panel drive control unit 11. The liquid crystal panel drive control section 11 generates 1/8 frame timing and line timing for polarity reversal according to the timing synchronized with the 8x speed sequential signal from the 8x speed sequential control section 2, and generates the liquid crystal panel. A signal for vertical scanning is generated and supplied to.

8 output from the field inversion circuit 12
The double-speed plane sequential signal is supplied to the liquid crystal panel 1 via the buffer 13.
4 is supplied. The liquid crystal panel 14 is a transmissive black-and-white liquid crystal panel, and is provided with a pixel matrix as a display area and a display drive circuit for driving each pixel in the display area. Specifically, a dot scan shift register corresponding to horizontal pixels and a line scan shift register for performing vertical scanning are provided. The 8 × -speed plane-sequential signal is fetched into the dot scan shift register for each line of data, and a vertical scan signal from the liquid crystal panel drive control circuit 11 is supplied to the line scan shift register. Is performed.

For a transmissive display operation, an RGB color backlight 1 is provided on the back side of the display area of the liquid crystal panel 14.
6 are arranged. In this example, the image signal of one frame is
As described above, signal R ′ → signal G ′ → signal B ′ → signal W →
8 in the order of signal W → signal B ′ → signal G ′ → signal R ′
A double-speed plane sequential signal is used, and a black-and-white image is displayed on the transmissive black-and-white liquid crystal panel 14 based on the signal.
Color display is performed by using the GB color backlight 16.

When the transmissive black-and-white liquid crystal panel 14 is used for color display, the number of pixels is reduced to 1/3 since the black-and-white liquid crystal panel has the same number of pixels as an image as compared with the use of a color liquid crystal panel. Become. The reduction in the number of pixels without deteriorating the image quality is achieved by the liquid crystal panel 2.
It also contributes to the miniaturization of zero. Also, from a different perspective,
With the same number of pixel configurations as the color liquid crystal panel, it is possible to increase the resolution by a factor of three. In this example, as will be described later, high image quality is realized by using the 8 × -speed plane sequential signal in the above order. In addition, the RGB color backlight 16 is caused to emit light to the transmission type monochrome liquid crystal panel 14 in a plane sequential manner. Thus, by performing color display, reduction in the number of pixels or higher resolution can be promoted.

The color display operation by the sequential light emission will be described with reference to FIGS. As shown in FIG. 3, a backlight 1 is provided on the back side of the display area of the liquid crystal panel 14.
The backlight 16 outputs red, green, and blue backlights, for example, by arranging a large number of R light-emitting LEDs, G light-emitting LEDs, and B light-emitting LEDs. be able to.

Further, as shown in FIG.
6a, the middle part 16b, and the lower part 16c are divided and set.
Each of the upper part 16a, the middle part 16b, and the lower part 16c,
It can output red, green and blue backlight light.
In addition, R light emitting LED, G light emitting LED, B light emitting L
By emitting light from all of the EDs, white light can be emitted and output. Then, as can be seen from the 8 × speed plane sequential signal shown in FIG. 2D, the liquid crystal panel 14 scans one screen by the signal R ′ in the first ８ period of one frame, and performs the next scan. Scanning for one screen by the signal G 'is performed in the 1/8 period. Similarly, 1/8 period (1 field)
Each time, scanning by the signal B ′, the signal W, the signal W, the signal B ′, the signal G ′, and the signal R ′ is performed.

In accordance with such scanning, the upper portion 16a, the middle portion 16b, and the lower portion 16c of the backlight 16 emit light at the timing shown in FIG. This upper part 16
The light emission operation of the middle part 16b and the lower part 16c is performed based on the timing from the backlight surface sequential drive control unit 15 and the information of the emission color instruction. The backlight surface sequential drive control unit 15 generates the light emission control timing based on the timing synchronized with the 8 × speed sequential signal from the 8 × speed sequential control unit 2.

An example of the light emitting operation will be specifically described with reference to FIGS. As shown in the lower part of FIG. 4, periods of each field as 1/8 period of one frame are indicated by periods F1 to F8. The periods obtained by further dividing each of the periods F1 to F8 into three are indicated by i, ii, and iii. For example, in the following description, “period F
1 (i) ”is the first 1/1 in the period of the field F1.
Three periods are shown. As can be seen from FIG. 4A, periods F1 and F8 are periods during which the liquid crystal panel 14 performs scanning with the signal R ′.
2, F7 is a period during which scanning by the signal G 'is performed. Further, periods F3 and F6 are periods during which the liquid crystal panel 14 performs scanning with the signal B ′.
F5 is a period during which scanning by the signal W is performed.

The upper part 16a, the middle part 16b, and the lower part 16
As a waveform representing the light emitting operation of c, the L level does not emit light, and at the H level, “R” indicates a red light emitting operation,
“G” is a green light emitting operation, “B” is a blue light emitting operation, and “RG”
"B" indicates a white light emission operation.

First, the period F1 (i) is viewed. This period F1
(I) is a period during which one-third of scanning of the signal R ′ for one screen is performed on the liquid crystal panel 14. That is, this is a period in which scanning is progressing in the upper third portion of the display area of the liquid crystal panel 14 facing the upper portion 16a. In this period, the scanning has not reached the portion facing the middle portion 16b and the lower portion 16c, and each pixel in the lower 2/3 region of the display region has the last field (period F8) of the immediately preceding frame. The data of the signal R ′ by scanning is held. It is needless to say that the data of the previous field is stored due to the function of retaining the pixel transmittance of the pixels of the liquid crystal panel.

In the period F1 (i), the state of the display area is as shown in FIG. In FIG. 5, an area being scanned is shown as a hatched portion. As shown in FIG. 5, in the period F1 (i), pixels in the upper third of the area are being scanned, and
The information of the signal R 'is held in the pixels in the area of / 3. Therefore, during this period F1 (i), as shown in FIG. 4, the light emitting operation is stopped in the upper part 16a, while the central part 1a is stopped.
6b and the lower part 16c are caused to execute a red light emission operation.

Subsequently, in the period F1 (ii), FIG.
As can be seen from (b), the pixels in the upper one-third area have been changed to the information of the signal R ′ scanned immediately before, and the center one-third.
Area is being scanned, and information of the signal R 'of the previous field is held in the pixels of the lower third area. Therefore, during this period F1 (ii), as shown in FIG. 9, the upper part 16a executes the red light emission operation, the middle part 16c stops the light emission operation, and the lower part 16c continues the red light emission operation.

In the period F1 (iii), FIG.
As can be seen from (c), the pixels in the upper 2/3 region have been changed to the information of the signal R 'scanned immediately before, and the pixels in the lower 1/3 region are being scanned. Therefore, during this period, as shown in FIG. 9, the upper part 16a and the middle part 16b execute the red light emission operation, and the lower part 16c stops the light emission operation.

From the period F2 (i), scanning by the signal G 'is started. As shown in FIG. 10D, the period F2
In (i), the pixels in the upper 1/3 region are being scanned and the lower 2/3
The information of the signal R ′ is held in the pixels in the area of “1”. Therefore, during this period, as shown in FIG. 9, the upper part 16a stops the light emitting operation, while the middle part 16b and the lower part 16c execute the red light emitting operation.

Similarly, the light emitting operation of the upper portion 16a, the middle portion 16b, and the lower portion 16c is performed in each 1/3 period of one field in accordance with the scanning position on the liquid crystal panel 14 and the information held therein, as shown in FIGS. 5 is controlled. As described above, the color image is displayed by performing the scanning of the liquid crystal panel 14 in accordance with the 8 × speed sequential signal and the sequential emission of the backlight 16.

In this example, the light-emitting area of the backlight 16 is divided into three, and the light-emitting state is switched at intervals of 1/3 of one field. However, the number of divisions of the light-emitting area of the backlight 16 is arbitrary. Can be set to That is, if the number of divisions of the light emitting region is “Y”, one field period is divided into Y periods, and the light emitting state of each light emitting region may be switched.

As described above, in this example, the signal R '→ signal G'
A black-and-white image is displayed on the transmissive black-and-white liquid crystal panel 14 on the basis of an 8 × speed plane sequential signal in the order of → signal B ′ → signal W → signal W → signal B ′ → signal G ′ → signal R ′. In this case, color display is performed by the RGB color backlight 16 emitting light sequentially in a plane. As described above, by performing the color display by the three-part screen emission sequentially, the resolution of the displayed image can be increased.

FIGS. 6A and 6B show the state on the screen and the state on the retina in the case of the present embodiment as in FIGS. 13 to 15 described above. That is, this is a state in which the eyeball follows a moving edge portion of a single color change in which a change in the white signal W is large.

In FIG. 6A, 1 V (one frame) is arranged on the time axis for two frames in the vertical direction, and the moving direction of the image is shown on the horizontal axis. That is, by displaying the image of the lower frame following the image of the upper frame, the edge of the displayed image moves rightward in the drawing. The numbers in the figure are luminance levels. The points MA and MB as arrows pointing to the lower right in the figure indicate a certain point on the retina of the viewer. When considering the movement of the display image as shown in these two frames, the eyeball of the viewer follows the movement of the display image, whereby the MA point and the MB point on the retina relatively move with respect to the image. Move like an arrow.

The upper part of FIG. 6B shows an image of two frames with the MA point and MB point on the retina as reference (fixed) when the eyeball follows. The image (color) recognized on the retina is shown in the lower part of FIG. As can be seen by comparing FIG. 6B in the case of this example with FIGS. 14 and 15 described above, the MA point and the MB on the retina as the moving edge portions of the monochromatic change in which the change of the component of the white signal W is large. The state of the image edge recognized between the points is to reduce the level of white cracks as compared with the case of the quadruple speed sequential method shown in FIG. 14, as in the case of the 8 × speed sequential method shown in FIG. Can be. And furthermore,
It can be seen that two white cracks appearing in the example of FIG. 15 have been reduced to one in this example. Further, in this example, the moving edge portion between the achromatic colors is an edge having no color breakage and having no false contour, similarly to the quadruple speed sequential method. That is, in this example, an 8 × speed plane sequential signal is used, and further, the signal W is configured to be continuous for two fields, thereby realizing high image quality.

In this embodiment, the liquid crystal panel 14 is a transmissive black-and-white liquid crystal panel. However, a configuration using a reflective black-and-white liquid crystal panel is also conceivable. In this case, instead of the RGB color backlight 16, the front of the liquid crystal panel 14 is replaced. An RGB color front light disposed on the side may be provided.
The configuration of the other circuit units and the operations such as field sequential scanning and field sequential emission are the same.

As another example of the display portion, a black and white CRT is used in place of the liquid crystal panel 14 and the backlight 16 of FIG.
(Cathode ray tube) and liquid crystal color shutter, black and white CR
A structure in which a liquid crystal color shutter is arranged in front of the T is also conceivable. An operation example of the display part when this structure is employed will be described with reference to FIGS. FIG. 7A shows a structure in which a liquid crystal color shutter 41 is arranged on the front of a monochrome CRT 42. As described above, the signal R ′ is applied to the monochrome CRT 42.
→ Signal G ′ → Signal B ′ → Signal W → Signal W → Signal B ′ → Signal G ′ → Signal R ′ An 8 × speed sequential signal is applied in this order, and scanning is performed based on the 8 × speed sequential signal. This is a high-brightness cathode ray tube that sequentially displays black-and-white images as images. Light emitted from the black-and-white CRT 42 passes through a liquid crystal color shutter 41 disposed in front of the cathode-ray tube, whereby a color image can be formed. It has become.

The liquid crystal color shutter 41 is a monochrome C
The structure is divided into an upper portion 41a, a middle portion 41b, and a lower portion 41c corresponding to the vertical direction of the display surface of the RT.
Each of the upper part 41a, the middle part 41b, and the lower part 41c can control the transmission state of each of the red light R, the green light G, the blue light B, and the white light W by the structure described with reference to FIG. As shown in FIG. 8, each of the upper part 41a, the middle part 41b, and the lower part 41c has a color polarizer 51, 53, 55.
And two liquid crystal cells 52 and 54 constituting a liquid crystal shutter
It is constituted by.

In this case, the liquid crystal cells 52 and 54 are liquid crystal (for example, nematic, smectic, FLC).
0) or half-wavelength delay for a specific wavelength using birefringence or optical activity (rotation), that is, when its polarization plane is polarized by 90 ° and the drive is turned off. A state is obtained in which light of a color having a specific polarization plane previously set by the color polarizing plates 52 and 54 is polarized by 90 °. On the other hand, when the light is turned on, incident light is reduced. The light is transmitted as it is.

The color polarizing plates 51, 53, 55 are formed so as to have the following characteristics. Color polarizing plate 51: B light is transmitted from the horizontal polarization axis, and R light, G light, and B light are transmitted from the vertical polarization axis. The color polarizing plate 53 transmits R light from the horizontal polarization axis, and transmits R light, G light, and B light from the vertical polarization axis. The color polarizing plate 55 transmits G light from the horizontal polarization axis, and transmits R light, G light, and B light from the vertical polarization axis.

Such color polarizing plates 51, 53, 55
And an upper portion 41a, a middle portion 41b, and a lower portion 4 of a liquid crystal color shutter 41 constituted by liquid crystal cells 52 and 54.
By changing the combination of the on / off states of the liquid crystal cells 52 and 54, each of 1c includes red light R, green light G, blue light B, and white light W as the light passing through the last color polarizer 55. It is possible to switch so that only one color of light is selectively transmitted.

FIG. 8 shows a state in which light of each color is selectively transmitted.
(A) to (d). FIG. 8A shows the B light, and FIG.
8C shows a state in which G light, FIG. 8C shows a state in which W light is selected, and FIG. 8D shows a state in which R light is selected.

When transmitting the B light, as shown in FIG. 8A, the liquid crystal cell 52 is turned off and the liquid crystal cell 54 is turned off.
Is turned on. In this case, the R light, the G light, the B light transmitted through the vertical polarization axis of the color polarizing plate 51, and the B light transmitted through the horizontal polarization axis are polarized by 90 ° in the liquid crystal cell 52 which is turned off. The light reaches the color polarizing plate 53. Then, in the color polarizing plate 53, only the B light is transmitted from the vertical polarization axis, and only the R light is transmitted from the horizontal polarization axis, and reaches the liquid crystal cell. Since the liquid crystal cell 54 is turned on, the B light and the R light pass through as they reach the color polarizer 55, where the R light of the horizontal polarization axis is blocked, and only the B light is transmitted.

When transmitting the G light, the liquid crystal cell 52 is turned on and the liquid crystal cell 54 is turned on as shown in FIG.
Is turned off. In this case, the R light, the G light, the B light transmitted through the vertical polarization axis of the color polarizing plate 51, and the B light transmitted through the horizontal polarization axis pass through the liquid crystal cell 52 which is turned on and pass through the color polarizing plate 53. To reach. Then, in the color polarizing plate 53, the R light, the G light, and the B light are transmitted from the vertical polarization axis, and the B light of the horizontal polarization component is blocked here. The R light, G light, and B light transmitted through the vertical polarization axis pass through the liquid crystal cell 54 which is turned off, so that the polarization component is polarized by 90 ° and reaches the color polarizer 55. Only the G light deflected in the horizontal direction among the R light, the G light, and the B light is transmitted.

When transmitting W light, as shown in FIG. 8C, both the liquid crystal cell 52 and the liquid crystal cell 54 are turned on. Then, the R light, the G light, the B light transmitted through the vertical polarization axis of the color polarizing plate 51, and the B light transmitted through the horizontal polarization axis pass through the liquid crystal cell 52 and reach the color polarizing plate 53. In the color polarizing plate 53, R light, G light, and B light are transmitted from the vertical polarization axis, and B light is blocked from the horizontal polarization axis. In addition, R light, G light,
Since the B light passes through the liquid crystal cell 54 which is turned on as it is, the R light, the G light, and the B light, that is, the W (white) light pass through the color polarizing plate 55.

When transmitting the G light, the liquid crystal cells 52 and 54 are turned off as shown in FIG. in this case,
R light, G light transmitted through the vertical polarization axis of the color polarizing plate 51,
The B light and the B light transmitted through the horizontal polarization axis reach the color polarizer 53 with the polarization component polarized by 90 ° by the liquid crystal cell 52 that is turned off. Then, in the color polarizing plate 53, only the B light is transmitted from the vertical polarization axis, and only the R light is transmitted from the horizontal polarization axis, and reaches the liquid crystal cell. Since the liquid crystal cell 54 is turned off, the polarized light component is polarized by 90 ° and reaches the color polarizer 55, where the B light is blocked and only the R light is transmitted.

As can be seen from the above description, the upper portion 41a, the middle portion 41b, and the lower portion 41c of the liquid crystal color shutter 41.
Can set red light R, green light G, blue light B, and white light W as transmitted light by setting a combination of on / off states of the liquid crystal cells 52 and 54 as shown in FIG. . Therefore, the upper part 41a, the middle part 41b, and the lower part 41c each switch the transmitted light in synchronization with the scan corresponding to the 8 × -speed plane sequential signal executed in the monochrome CRT 42, thereby enabling color display. That is, each of the upper part 41a, the middle part 41b, and the lower part 41c may switch the transmitted light at the same timing as in FIG.

In FIGS. 4B, 4C, and 4D, the light shown as the emission colors R, G, B, and RGB (w) at each timing is transmitted through the colors R, G, and B in the case of FIG. , R
GB (w). The scanning timing according to the 8 × speed sequential signal in the monochrome CRT 42 and the switching timing of the transmitted light correspond to the scanning timing according to the 8 × speed sequential signal of the liquid crystal panel 14 described with reference to FIGS. The timing is exactly the same as the timing of switching the 16 emission colors, so the description is omitted. Similarly, higher resolution can be realized by upper and lower three-part transmitted light control corresponding to such image scanning.

Although the embodiment has been described above, the present invention can be embodied in various other modifications. First, various examples of the form of the display portion may be considered in addition to the above examples. Further, in the above example, the 8 × speed plane sequential signal is represented by a signal R ′ → signal G ′ → signal B ′ → signal W → signal W →
Although an example has been described in which the signal B ′ → signal G ′ → signal R ′ is an 8 × -speed plane sequential signal, other examples are possible as long as at least the signal W is in an order of continuous two fields. For example, signal B ′ → signal G ′ → signal R ′ → signal W → signal W →
8 × speed plane sequential signal in the order of signal R ′ → signal G ′ → signal B, or signal R ′ → signal G ′ → signal B ′ → signal W → signal W → signal R ′ → signal G ′ → signal B May be used as an 8 × speed plane sequential signal.

[0056]

As described above, in the present invention, each of the red signal, the green signal, the blue signal, and the white signal is performed twice in one frame period, and at least the white signal is continuous for two field periods. Since the display operation is performed by using the 8 × -speed surface sequential signal described above, color breaks and white breaks can be reduced and pseudo contours can be eliminated, thereby achieving an effect of realizing high-resolution display.

[Brief description of the drawings]

FIG. 1 is a block diagram of a display device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of 8 × speed sequential output of the display device according to the embodiment;

FIG. 3 is an explanatory diagram of a liquid crystal panel and a backlight according to the embodiment.

FIG. 4 is an explanatory diagram of a light emitting operation of the backlight according to the embodiment.

FIG. 5 is a diagram illustrating a relationship between a light emission operation of a backlight and a scanning timing according to the embodiment.

FIG. 6 is an explanatory diagram of a state on a screen and a retina in the display device according to the embodiment;

FIG. 7 is an explanatory diagram of another structure example of the display means of the embodiment.

FIG. 8 is an explanatory diagram of a liquid crystal color shutter in another structural example of the display means of the embodiment.

FIG. 9 is an explanatory diagram of a control pattern of a liquid crystal color shutter in another structural example of the display means of the embodiment.

FIG. 10 is a block diagram of a white signal generation unit for quadruple-speed plane sequential output.

FIG. 11 is an explanatory diagram of a state on a screen and a retina in a conventional triple speed plane sequential system.

FIG. 12 is an explanatory diagram of a state on a screen and a retina in a conventional quadruple speed sequential method.

FIG. 13 is an explanatory diagram of a state on a screen and a retina in a conventional triple speed plane sequential system.

FIG. 14 is an explanatory diagram of a state on a screen and a retina in a conventional quadruple speed sequential method.

FIG. 15 is an explanatory diagram of a state on a screen and a retina in a conventional 8 × speed plane sequential system.

[Explanation of symbols]

Reference Signs List 1 A / D converter, 28x speed plane sequential control unit, 3 frame memory, 4, 5, 6 reverse γ correction unit, 7 white signal generation unit, 8 selector, 9 γ correction circuit, 10 D /
A converter, 11 liquid crystal panel drive control unit, 12 field inversion circuit, 13 buffer, 14 transmission type monochrome liquid crystal panel, 15 backlight surface sequential drive control unit, 16
RGB color backlight, 41 liquid crystal color shutter, 42 monochrome CRT

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 11/20 H04N 11/20 (72) Inventor Takao Takahashi 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Keiichi Nito 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (6)

[Claims] 1. A display for generating a red signal, a green signal, a blue signal, and a white signal, which are signals of a field period obtained by dividing one frame period into eight, as display control signals from an input color image signal. A control signal generating unit, wherein, during one frame period, each of the red signal, the green signal, the blue signal, and the white signal generated by the display control signal generating unit is twice, and at least the white signal is Plane-sequential output means for outputting an 8 × -speed plane-sequential signal so as to be continuous for two field periods; and display means for performing a display operation using the 8-times-speed plane-sequential signal output from the plane-sequential output means. Characteristic display device. 2. The display means comprises: a transmissive black-and-white liquid crystal panel; and an RGB color backlight that performs a light-emitting operation from the rear side of the transmissive black-and-white liquid crystal panel. The RGB color backlight is driven by an 8 × -speed plane-sequential signal output from the means, and emits red, green, blue, and white plane-sequential light at timing based on the 8 × -speed plane-sequential signal. The display device according to claim 1, wherein the display device performs color display. 3. The display means comprises a reflective black-and-white liquid crystal panel and an RGB color front light for emitting light from the front side of the reflective black-and-white liquid crystal panel. The RGB color front light emits red, green, blue, and white colors in a sequential manner at a timing based on the 8x speed sequential signal, while being driven by an 8x speed sequential signal output from the means. The display device according to claim 1, wherein the display device performs color display. 4. The display means comprises a black-and-white cathode-ray tube and a liquid crystal color shutter disposed in front of the black-and-white cathode-ray tube. In addition to being driven by a signal, the liquid crystal color shutter performs color display by performing plane-sequential transmission output of each color of red, green, blue, and white at a timing based on an 8 × speed plane-sequential signal. The display device according to claim 1. 5. A red signal, a green signal, a blue signal, and a white signal, each being a signal of a field period obtained by dividing one frame period into eight, are generated as display control signals from an input color image signal, In one frame period, each of the red signal, the green signal, the blue signal, and the white signal is twice, and at least the white signal is 2
An output is performed in an 8 × -speed plane sequence so as to be continuous in a field period, and a display operation is performed based on the red signal, the green signal, the blue signal, and the white signal output in the 8 × -speed plane sequence. Display method. 6. The output of the red signal, the green signal, and the blue signal is sequentially performed in the first three fields of one frame period as the eight-time speed sequential output, and is performed in the next two fields. 6. The field signal according to claim 5, wherein the field signal based on the white signal is repeated twice, and the output of each field signal based on the red signal, the green signal, and the blue signal is sequentially performed in the last three fields. Display method.